My Oracle Support Banner

Increased Concurrent SMTP Connections and STARTTLS Timeout After Upgrading to (Doc ID 2482821.1)

Last updated on APRIL 07, 2022

Applies to:

Oracle Communications Messaging Server - Version 8.0.2 and later
Information in this document applies to any platform.


The following behavioral changes were observed after patching Messaging Server / MTA to update from to

Number of concurrent connections to port 25 on the MTA bumped.

Started to get alarms from msprobe because it was taking longer than normal to connect to port 25.

The flag 'ct=600' is the key. That shows the connection lasted 10 minutes.  So they were stuck in STARTTLS for 10 minutes.

Connections which were previously working in a relatively normal/short length of time are now stuck for 10 minutes waiting for STARTTLS to complete.  That drives up the number of concurrent (mostly unproductive) connections.
Which puts us over the MAX_PROCS x MAX_CONNS limit. So the dispatcher is unable to accept any new connections. So clients time out.

The load-balancer (LB) see this as the server being unresponsive, takes it out of the VIP, which causes the load to drop the LB then sees it as responsive again, starts sending new connections to it, lather, rinse, repeat…

Could there be any change between Messaging Server and which might explain this behavior change?


Issue started after patching Messaging Server / MTA from to


To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document
 Increased number of concurrent SMTP connections
 Alarms on server response time
 Additional Symptom: server flapping
 Support for SSL version 2 CLIENT-HELLO Removed
 Support for NSS 3.41

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.